The invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), has resulted in increased use of insecticides on horticultural crops in the Mid-Atlantic US, which has diminished integrated pest management (IPM) programs that worked well otherwise. The research herein explored the use of three new tools in the development of BMSB management strategies. In one study, a BMSB pheromone lure was placed on insecticide-incorporated mesh netting to be used in an attract-and-kill strategy to protect bell peppers. The pheromone and netting deployed within a pepper field resulted in more BMSB feeding on plants within 6.1 m to the attract-and-kill screen than in further peppers or peppers in the weekly insecticide treatment. In another study, the insecticidal netting used as a row cover reduced stink bug damage to peppers, but also caused significant yield losses, possibly due to lack of light and/or pollination. The BMSB pheromone lure was also utilized in a sticky trap-based action threshold for insecticide application decisions. The trap and lure predicted densities of bugs on pepper plants and the use of an action threshold of 5 bugs per trap per week to trigger an insecticide spray reduced insecticide applications by 50% at one location, however population densities were lower at the other two locations and significance was not found among treatments. Lastly, BMSB is a nuisance pest to homeowners so we tested the exclusion efficacy of repellents on overwintering shelters and found an 8-fold reduction in BMSB that entered shelters treated with geranyl cyclopentanone (apritone). The use of BMSB pheromones paired with insecticide netting for attract-and-kill of BMSB, the development of action thresholds using captures in pheromone-baited sticky cards, and the use of apritone as a repellent are all promising IPM strategies worth refining in future studies. / MSLFS / The brown marmorated stink bug (BMSB) has become a serious household nuisance and agricultural pest in the US. BMSB feeds on and damages a large variety of crops including, fruits, vegetables, and field crops. Most growers of high value crops have increased their insecticide usage to battle this bug; thus, more sustainable integrated pest management (IPM) approaches need to be established. One main vegetable crop that BMSB damages is bell peppers. One study tested the efficacy of an attract-and-kill approach involving a BMSB pheromone lure paired with insecticide-impregnated mesh netting. When deployed in pepper fields, it was found that BMSB stayed on plants rather than receiving a lethal dose from the netting. Another study tested the netting as a row cover or as a fence between peppers and found that it did little at preventing damage. Furthermore, pepper yields were significantly lower under the row cover treatment. In another study, a clear sticky panel placed on a stake and paired with a BMSB pheromone lure was used to assist in making management decisions based on relative densities of bugs in plots. This can help determine if insecticide applications are needed. Not only is BMSB a pest of agriculture, but it is also a nuisance pest to homeowners when adults seek winter shelter during their fall dispersal period, sometimes entering homes by the thousands. The tactile repellent, geranyl cyclopentanone (apritone), was found to elicit an 8-fold reduction in the number of overwintering BMSB in overwintering shelters.

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive agricultural and nuisance pest in the United States and an increasing number of countries abroad. In the absence of other long-term solutions, biological control presents one of the most promising H. halys management options. An adventive population of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), one of the most effective egg parasitoids of H. halys in their shared native range in Asia, was discovered in the Maryland in 2014 and in Frederick County, VA in 2015. Adventive populations of T. japonicus have also been detected recently in several other states and show strong indications of ongoing range expansion. Despite their importance, the foraging ecology of H. halys and especially of T. japonicus in the USA need further study. Small pyramid traps baited with a low-dose H. halys aggregation pheromone lure and deployed as vertical transects in the canopy of female tree of heaven (Ailanthus altissima (Mill.) Swingle), male tree of heaven, or hackberry (Celtis occidentalis L.), captured significantly more H. halys adults and nymphs near the top of the canopy than at mid- or lower canopy, regardless of host plant. The majority of H. halys egg masses collected via destructive sampling of felled tree of heaven were from mid-canopy, and the majority of those parasitized by T. japonicus were also from mid-canopy, with no T. japonicus emergence from egg masses collected from the lower canopy. A comparison of sentinel H. halys egg masses and yellow sticky traps deployed as vertical transects in tree of heaven revealed that the majority of T. japonicus detections occurred at mid-canopy and that while both methods proved to be equally effective, yellow sticky traps were more efficient for this purpose. This led to the development of a novel T. japonicus sampling method in which a yellow sticky trap is deployed atop a bamboo pole in the mid-canopy of wild host trees. This method was employed to compare the effect of habitat type on T. japonicus captures in female tree of heaven growing in spatially isolated patches, thin windbreaks, and at the edge of contiguous woodlots. Consistent habitat effects on T. japonicus detections were not found between sampling years, but provided the first documentation of the seasonal activity of T. japonicus in the USA. A study of host plant effects on T. japonicus detection in mid-canopy yellow sticky traps did not reveal consistent host plant effects on captures. These data provide important insights into the foraging ecology of H. halys and T. japonicus in the USA, as well as efficient sampling methods for future studies of T. japonicus. / Doctor of Philosophy / The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive agricultural and nuisance pest from Asia that is widely distributed in the United States and is present in an increasing number of countries abroad. In the absence of other long-term management solutions, biological control via the actions of natural enemies presents a promising brown marmorated stink bug management option. Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), also known as the samurai wasp, is one of the most effective egg parasitoids of brown marmorated stink bug in Asia. Samurai wasp arrived in the USA without deliberate introduction and was first detected in Maryland in 2014 and subsequently in Frederick County, VA in 2015. It has continued to expand its range in the USA and was recently detected in several eastern and western states. Despite their importance, little is known of where brown marmorated stink bug eggs, nymphs, and adults are most likely to be found in wild trees. Even less is known about where samurai wasp is likely to occur within its new range. To address these issues, traps containing a lure to attract brown marmorated stink bug were placed in the upper, middle, and lower canopy of female tree of heaven (Ailanthus altissima (Mill.) Swingle), male tree of heaven, and hackberry (Celtis occidentalis L.). Significantly more brown marmorated stink bug adults and nymphs were caught in traps near the top of trees than in those at other canopy locations, with no effect of host plant species observed. The majority of brown marmorated stink bug egg masses collected from felled tree of heaven were from the middle of the canopy. The majority of samurai wasps emerged from egg masses collected from the mid-canopy, while none emerged from those collected from the lower canopy. In a comparison of sentinel brown marmorated stink bug egg masses and yellow sticky traps placed in the upper, middle, and lower canopy of tree of heaven, the majority of samurai wasp detections occurred at mid-canopy. Both methods were found to be effective, but yellow sticky traps required less time and effort to use. This led to the development of a new sampling method for samurai wasp, in which a yellow sticky trap was deployed atop a bamboo pole in the mid-canopy of wild host trees. Using this technique, the effect of habitat type on samurai wasp captures was examined, revealing no consistent effects on detections. However, this study provided the first documentation of when samurai wasps are present and most abundant during the spring and summer. A study of host plant effects on samurai wasp captures, also using yellow sticky traps placed in the mid-canopy of trees, did not reveal consistent host plant effects on captures. These data provide important insights into the interactions of brown marmorated stink bug, samurai wasp, and their environment in the Mid-Atlantic region of the USA, as well as an efficient tool with which to study the samurai wasp.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), an invasive agricultural pest from Asia, has established in much of the USA, where it has had significant, deleterious impacts on the production of various specialty crops. Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is the predominant egg parasitoid of H. halys in Asia and considered a potential agent for classical biological control. Adventive T. japonicus populations have been detected in 15 US states since 2014 and its continued spread is anticipated, creating the impetus for developing optimized sampling methods for it that are informed by its foraging ecology. Yellow sticky cards (YSC) deployed in the lower and mid-canopy of Ailanthus altissima (Mill.) Swingle trees in Virginia captured statistically equivalent numbers of T. japonicus. Season-long monitoring of T. japonicus and H. halys over two seasons resulted in significant correlations between captures of T. japonicus and H. halys adults, second instar nymphs, and all life stages combined, revealing spatiotemporal synchrony between the parasitoid and its host. Inspection of felled pheromone-baited and non-baited A. altissima showed no effect of baiting with the H. halys aggregation pheromone on H. halys egg mass abundance. Similarly, captures of T. japonicus in pheromone-baited and non-baited trees were not significantly different. Augmenting YSC with H. halys egg masses or n-tridecane did not improve T. japonicus captures. Together, these results should improve the efficiency of T. japonicus surveillance efforts and provide important guidance for future research toward enhancing the sensitivity of sampling tools for it and the interpretation of its impacts on H. halys. / Master of Science in Life Sciences / The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), an invasive species from Asia, has become widely distributed throughout the United States as a serious pest of many important crops. Parasitic wasps that develop on eggs are often key natural enemies for reducing stink bug populations. The samurai wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), is the primary parasitic wasp of BMSB in Asia and is under evaluation for potential use in biological control programs. Populations of samurai wasps have been detected in the United States since 2014 without intentional introduction. Its continued spread is anticipated, creating the need for effective sampling methods to track its establishment. Yellow sticky cards (YSC) deployed in the lower and mid-canopy of tree of heaven in Virginia captured similar numbers of samurai wasps. Season-long monitoring of samurai wasps and BMSB over two seasons resulted in significant correlations between captures of samurai wasps and BMSB adults, second instar nymphs, and all life stages combined, revealing spatiotemporal overlap between the wasp and its host. Inspection of felled pheromone-baited and non-baited tree of heaven showed no effect of baiting with the BMSB aggregation pheromone on numbers of BMSB egg masses. Similarly, captures of samurai wasps in pheromone-baited and non-baited trees were not significantly different. Combining YSC with BMSB egg masses or n-tridecane did not improve samurai wasp captures. Together, these results provide important guidance for future research toward enhancing the sensitivity of sampling tools for samurai wasps and the interpretation of its impacts on BMSB.

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species that has spread throughout the United States and become a serious agricultural pest. Studies were conducted in Virginia on the survival of H. halys nymphs on different vegetable hosts and on the oviposition preference of H. halys on common tree hosts in southwestern Virginia. To determine the effects of vegetable host on H. halys survival, nymphs were placed on one of five vegetable host plants and their corresponding vegetable fruit. Survival was highest on sweet corn, followed by bell pepper and snap bean. Eggplant and tomato were poor compared to other vegetable hosts tested, potentially due to secondary compounds released by the plant to reduce feeding. Of six common host trees sampled, H. halys laid the most egg masses on catalpa, Catalpa bignonioides, while aggregation lure had no effect on the number of eggs laid. Across host trees, egg masses were more commonly found in trees with fruiting structures present. An additional study was conducted on a red-sternum phenotype of H. halys. Mortality was recorded by sternum phenotype for each sex. There was no difference in survival between groups at two time points. Biochemical tests were used to determine if the red-sternum was associated with the potentially pathogenic red bacteria Serratia marcescens. Only one stink bug's gut contents had a confirmed infection of S. marcescens. Results from these studies offer insight into H. halys development on vegetable hosts and oviposition preferences on different host trees. / MSLFS / The brown marmorated stink bug (BMSB), is an invasive insect that has spread throughout the United States and become a serious pest. Current research is focused on reducing their populations without increasing insecticide use. Studies were conducted to determine if vegetable host type influenced survival and development of this insect. Nymphs were placed on one of five vegetable plants with the corresponding vegetable fruit. Overall, survival was highest on sweet corn, followed by bell pepper and snap bean. Eggplant and tomato were poor hosts, potentially due to chemicals released by the plant to reduce insect feeding. Six common host trees of BMSB were sampled to determine where females lay the most egg masses and the effect of using an attraction lure. Catalpa trees had the most egg masses throughout the season. Use of a lure had no effect on the number of eggs laid on any tree. A red colored abdomen was observed in some adult insects throughout these studies. To determine if this was associated with higher mortality, male and female insects were observed for two weeks. There were no mortality differences at either seven or 14 days between any of the groups. Tests were used to determine if the red abdomen was caused by a red-colored bacterium. Of the insects sampled, there was only one stink bug with a confirmed infection. Results from these studies provides information that increases knowledge of this pest’s ecology in Virginia.

For the first time in many decades, a hemp pilot program was initiated in Virginia in 2016. Outdoor surveys were conducted in the 2017 and 2018 field seasons to record insect presence and feeding injury to plants. Multiple insect pests were present, including corn earworm (Helicoverpa zea [Boddie]) (Lepidoptera: Noctuidae), brown marmorated stink bug (Halyomorpha halys [Stål]) (Hemiptera: Pentatomidae), and cannabis aphid (Phorodon cannabis) (Hemiptera: Aphididae). In 2019, indoor production surveys revealed that cannabis aphid, twospotted spider mite (Tetranychus urticae Koch) (Acari: Tetranychidae), and hemp russet mite (Aculops cannabicola [Farkas]) (Acari: Eriophyidae) would likely cause production issues. Very little is known about the impact of insect defoliation in hemp so studies were conducted in 2018-2020 to determine impacts on yield and cannabinoid content of grain and cannabinoid variety hemp due to leaf surface area loss. In Virginia over two growing seasons, manual removal of leaf tissue in grain and CBD cultivars did not significantly impact observable effects on physical yield (seed or bud weight) or cannabinoid content (CBD or THC) at time of harvest. Corn earworm is the major pest of hemp produced outdoors and studies occurred to evaluate monitoring and management strategies. Pheromone traps may be valuable in determining when corn earworm moths are present in the vicinity of hemp fields but are not useful in predicting larval presence in buds or final crop damage. Larval presence and final crop damage are related. Brown marmorated stink bug does not appear to be a concern in hemp, at least at this time. / Doctor of Philosophy / For the first time in many decades, a hemp pilot program was initiated in Virginia in 2016. Outdoor surveys were conducted in the 2017 and 2018 field seasons to record insect presence and feeding injury to plants. Multiple insect pests were present, including corn earworm, brown marmorated stink bug, and cannabis aphid. In 2019, indoor production surveys revealed that cannabis aphid, twospotted spider mite, and hemp russet mite would likely cause production issues. Very little is known about the impact of leaf area loss due to insect feeding in hemp so studies were conducted in 2018-2020 to determine impacts on yield and cannabinoid content of grain and cannabinoid variety hemp due to leaf surface area loss. In Virginia over two growing seasons, manual removal of leaf tissue in grain and CBD cultivars did not significantly impact observable effects on physical yield (seed or bud weight) or cannabinoid content (CBD or THC) at time of harvest. Corn earworm is the major pest of hemp produced outdoors and studies occurred to evaluate monitoring and management strategies. Pheromone traps may be valuable in determining when corn earworm moths are present in the vicinity of hemp fields but are not useful in predicting larval presence in buds or final crop damage. Larval presence and final crop damage are related. Brown marmorated stink bug does not appear to be a concern in hemp, at least at this time.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), brown marmorated stink bug, is an invasive, polyphagous pest that has disrupted integrated pest management programs in Mid-Atlantic tree fruit orchards since 2010. The amount of damage to fruit caused by H. halys feeding is highly variable, even within adjacent orchard blocks, and the influence of orchards and wild host plants nearby on H. halys relative abundance is unknown. Pheromone-based trapping studies conducted along woodland-to-orchard transects, along woodland borders at sites with and without adjacent orchards, and within the mid-canopy of several common wild host trees in woodland borders were used to investigate biotic factors underlying the variability of H. halys populations among sites within a geographically proximate area. Additionally, the retention duration of H. halys on wild and cultivated tree hosts was used as a proxy for host acceptability throughout the season. All trapping studies yielded significantly greater H. halys captures during the late season, and in the transect study, pyramid traps deployed at orchard and woodland edges during this period yielded the highest captures. The presence of orchards or open fields adjacent to woodlands had no significant impact on H. halys captures in sticky traps deployed along wooded edges, but captures varied significantly among orchard and open field sites. Among 11 common wild host plant genera surveyed at these sites, five genera, Elaeagnus, Fraxinus, Lonicera, Ailanthus, and Sassafras, were significantly related to H. halys relative densities. Conversely, studies measuring captures in small pyramid traps within the canopy of wild tree hosts revealed no significant differences among hosts at any point in the season, suggesting that this approach might not be appropriate for assessing host plant suitability. Finally, harmonic radar trials assessing host plant retention as a proxy for host suitability revealed that adults released on peach and pheromone-baited apple trees had significantly greater retention durations than those released on non-host, grass, and that adult retention duration increased from the early to late season. In combination, results indicate that the risk posed by H. halys to cultivated orchard crops varied across locations and seasonally, and may be related to the species composition of wild host trees in adjoining woodlands. / Doctor of Philosophy / Brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive insect that has inflicted feeding damage on fruit grown in Mid-Atlantic orchards since 2010. The agricultural landscape in the Mid-Atlantic region complicates BMSB management, as many orchards are bordered by woodlots containing a variety of BMSB host plants. The amount of BMSB feeding injury at harvest can vary greatly among nearby orchards, and even within individual orchards, but it is unknown why these differences exist. Several BMSB trapping studies using pheromone-baited traps revealed that BMSB populations were greatest in the late-season, confirming previous work. Furthermore, captures in traps positioned in lines intersecting orchards and adjacent woodlots revealed late-season BMSB presence was greatest at the orchard and woodland edges. Captures in traps next to woodlots adjacent to orchards and open field sites indicated that the presence of orchards had no impact on captures, but that captures varied significantly among orchard sites and open field sites. A survey of the woody plants in the woodlots adjacent to these sites revealed that five host plant genera were strongly related to BMSB abundance. A study examining BMSB captures in small pyramid traps deployed in the canopy of several common wild tree hosts did not yield differences in captures among hosts at any point in the season, and thus was not a suitable method for assessing seasonal differences in BMSB host use. Finally, harmonic radar technology was used to assess how long BMSB remained on several wild and cultivated host plants at different points in the growing season, as a proxy for host suitability. Peach and pheromone-baited apple showed significantly greater adult retention durations than non-host, grass, and adults remained on host plants longer in the early than late season. Ultimately, these results should aid in the monitoring and management of BMSB by providing a broader understanding of factors underlying the presence and abundance of BMSB on a localized geographic scale.

Brown marmorated stink bug, Halyomorpha halys (Stål), is a crossover pest impacting agriculture and invading urban environments. Studies were conducted to better understand the management of the bug through its physiology, behavior and susceptibility to insecticidal intervention. Halyomopha halys exhibit great variability in overwintering site selection with choices including manmade structures and tree bark. Because of these diverse sites, the bug must have the ability to withstand varying conditions throughout the overwintering cycle. We were able to determine that H. halys is chill intolerant and capable of adapting its tolerance to temperatures by season, sex, and location of acclimation. The mean supercooling point (± SEM) in the winter in Minnesota was -17.06°C ± 0.13° and in Virginia was -13.90°C ± 0.09°. Laboratory experiments conducted in Blacksburg, VA were able to determine baseline lethal high temperatures over time against H. halys adults. To achieve 100% mortality, temperatures fell between 45°C and 50°C, 40°C and 45°C, and 42°C and 45°C, over 15-min, 1-h, and 4-h, respectively. Moving forward, we were able to utilize this information to develop heat treatment guidelines for export shipping cargo infested with overwintering H. halys. In a controlled field experiment, we determined that exposing the coldest areas of an infested vehicle to temperatures greater than 50°C for a minimum of 15 minutes resulted in 100% mortality of overwintering BMSB adults. In 2012 and 2013, citizen scientists were recruited through Virginia Cooperative Extension to assist in evaluating several in home light traps designed to help eradicate overwintering H. halys adults in homes. Over the course of the two year study, fourteen houses participated in the study with 72% of those houses having stink bug activity. It was found that the most effective trap was an aluminum foil pan trap. In 2013, the trap was 19 times more effective at catching stink bug adults than any other trap tested. In September of 2014, a near-field experiment was conducted to determine the residual efficacy of several recommended and labeled insecticides for treatment of homes against invading H. halys adults. This study used constructed window screen bags that were dipped in insecticide solution. After the initial treatment, bugs were exposed to the bags for 24h weekly, up to 54 days after treatment (DAT). It was determined that 2 DAT all insecticides had activity except for indoxacarb. All insecticides lost efficacy after 29 DAT except for lambda-cyhalothrin, beta-cyfluthrin, beta-cyfluthrin + imidacloprid, lambda-cyhalothrin + thiamethoxam, and dinotefuran, which had some measureable activity even after 40 DAT. Each of these insecticides contained a pyrethroid alone or in combination with a neonicotinoid. Laboratory bioassays were conducted to determine the LC50 values of clothianidin, dinotefuran, imidacloprid, and thiamethoxam against H. halys nymphs using a systemic application method. Those LC50 values were found to be 0.077, 0.013, 0.068, and 0.018 ppm, respectively. Field experiments conducted in Virginia in 2012 and 2013 showed a significant reduction of stink bug damage using two soil applications of neonicotinoid insecticides in pepper and tomato. In North Carolina, a single drip irrigation application significantly reduced stink bug damage in 2012 and 2014 using dinotefuran or imidacloprid. / Ph. D.

The brown marmorated stink bug (Halyomorpha halys) (Stål) is known for overwintering in human homes. Studies were conducted to understand the behavior of adult bugs in response to characteristics of potential overwintering structures including gap sizes, light, and presence of dead conspecifics. In a test where bugs were placed in increasingly tight boxes, most bugs settled in gaps 4.5 - 5.5 mm high. None settled in a space less than 3.5 mm high. In boxes with constant tightness, bugs tended to move to the back, and primarily settled along walls and in corners. In both box types, bugs tended to turn and face the cavity entrance during settling. In tests of responses of disturbed overwintering bugs to common household light bulbs over the course of a year, bugs were taken from shelters and exposed to lit bulbs. Bug responses were seasonal, with attraction to light bulbs in spring and summer, but little or no consistent response in fall or winter. The lack of response occurred more often at night than in afternoons. Because not all bugs survive the winter, corpses can accumulate. Single shelter-seeking H. halys were found not to respond to the presence of dead aggregations from the previous years unless touch was possible, in which case aggregations were joined. Dead aggregations from the same year had a repellent effect. Presence of a single dead bug from the same year did not provide any survivorship advantage to overwintering bugs. Results suggest possible improvements to trap shelters. / Master of Science in Life Sciences / The brown marmorated stink bug (Halyomorpha halys) is known for overwintering in human homes. This research investigated the responses of these bugs to some characteristics of overwintering structures, including crevice tightness preference, light sources, and dead bugs leftover from previous years. Tightness experiments indicated that bugs in crevices with hard walls prefer to settle in spaces between 4.5 and 5.5 mm high. Bugs also tended to stay on the floor, go back as far as they could, and face the entrance of the crevice. These findings will help improve overwintering box designs for collection and research, and will help pest control professionals focus their efforts. When bugs were disturbed and exposed to common household light bulbs, they tended to move toward the bulbs in late summer and in spring, but responded less in fall and winter, and responded more often in the afternoon than at night. Bugs were also exposed to other dead bugs in several ways. When lone bugs were exposed to groups of dead bugs from previous years, they went to them only if they could touch them. Single dead bugs had less of an impact. Exposure to groups of dead bugs from the same year drove live bugs away. Overwintering brown marmorated stink bugs do not appear to eat other bugs that have recently died. These results suggest several possible improvements to the designs of trap shelters used for research and control.

Brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), has become an important pest of soybean in the Mid-Atlantic US. To assess the influence of tree borders on BMSB infestations in soybean, twelve fields were sampled weekly using five 3-min visual counts of BMSB on tree of heaven (TOH) (Ailanthus altissima) and other host trees along a wooded border, on the adjacent soybean edge, 15 m and 30 m into the soybean field. At all locations, BMSB densities increased on TOH wooded borders in July, then, gradually moved into adjacent soybean borders later in the summer. BMSB did not move far from the field edge, with approximately half as many bugs being present at 15 m into the field and very few being detected 30 m into the field. These results validate the use of border sprays for BMSB control in soybean. Additional studies conducted in 2013 and 2014 compared a visual plant inspection method with a standard sweep net strategy for sampling BMSB. Overall, the two methods were highly correlated with a correlation coefficient of R=0.83. Visual inspection appears to be an effective method for assessing BMSB populations in soybean. One of the major factors affecting the distribution and establishment of invasive species is climate. The CLIMEX modeling software uses climatic and biological factors of species to predict the geographic risk for pest outbreaks. A climate simulation model was run with CLIMEX to determine the potential distribution of BMSB in Virginia based on temperature. To develop a more accurate model, factors like resource availability and source population would need to be considered. / Master of Science in Life Sciences

Building design, maintenance, and management can have significant impacts on accessibility and suitability for pest species. The brown marmorated stink bug, Halyomorpha halys (Stål), causes household nuisance pest problems because of its habit of using human homes as winter refuges. Studies were conducted to understand behaviors and characteristics relevant to this problem, including response to gravity, ability to pass through openings, responses to heat, and mortality estimations in wall assemblies. In the lab, winter shelter seeking bugs were shown to exhibit upward movement, and field observations of bugs on building exteriors gave similar results. In experiments testing the size limits on openings through which bugs could pass, height limited tests excluded most females at 4 mm, and all bugs at 3 mm. Pronotum width limited tests excluded most females at 8 mm and nearly all bugs at 7 mm. Accompanying measurements of over 900 bugs found an average female pronotum width of 8.33 mm and height of 4.03 mm, and male pronotum width of 7.47 mm and height of 3.50 mm, with minimum sizes indicating that only a small percentage of bugs will pass the smallest openings tested. Heat response experiments of shelter seeking bugs were first piloted outdoors, and then modified to be a forced choice indoor test. In outdoor tests on a flat plane wall section with alternating heated sections, bugs did not respond to thermal contrast but rather immediately walked off of the wall. In the indoor forced choice test, a box of four cavity walls was used. Bugs did not respond to the heated sections in either the adjacent or opposite configuration. Thermal simulation modeling was used to evaluate the possible effects of varying wall assembly materials and configurations on cold-related mortality of bugs overwintering in the cavity space behind cladding. Simulation results indicated that bugs electing to overwinter in the space between cladding and sheathing were at risk of freezing deaths, with mortality expectations increasing in better insulated buildings. The results of these studies will inform future control measures and impact studies in buildings. / Ph. D.